title: Xylose induces the phyllosphere yeast Pseudozyma antarctica to produce a cutinase-like enzyme which efficiently degrades biodegradable plastics.
abstract: There is a need to speed up the degradation of used agricultural mulch films that are made of biodegradable plastics (BPs) in the field. Treating them with BP-degrading enzymes could be a solution to this problem. A cutinase-like enzyme of yeast Pseudozyma antarctica (PaE) has wide specificity of BPs degradation, but needs to be produced efficiently. Here we report that the production of PaE by P. antarctica can be increased by using xylose as carbon source. BP-degradation activity was analyzed using a polybutylene succinate-co-adipate (PBSA) emulsion as the substrate. Strain P. antarctica GB-4(1)W was found to be the best PaE producer among the tested strains. Using a 5-L jar fermentor with xylose fed-batch cultivation, high PaE productivity could be maintained and about 21 U/ml of PaE was obtained in 120 h. This amount was 100 times higher than the amount that we obtained previously (0.21 U/ml by flask cultivation using glycerol as carbon source). Under repeated xylose fed-batch cultivation with 24 h intervals, the maximum PaE production rate (0.34 U/ml/h) was maintained and the highest PaE productivity (28,000 U/2 L/d) was repeatedly obtained for 7 intervals. The activity of filtered jar-culture (crude PaE) was stable over 12 weeks at 4°C. Commercially available BP mulch films (20 μm thickness, cut into 1-cm-squares) were completely degraded by submerging them in crude PaE (2 U/ml) at 30°C in 24 h. These results indicated that concentrated PaE can rapidly degrade the strength of BP mulch films in the field so that they do not interfere with plowing.
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan; Research Fellow of the Japan Society for the Promotion of Science, Japan.
authors.forename: Takashi
authors.initials: T
authors.lastname: Watanabe
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan; Research Fellow of the Japan Society for the Promotion of Science, Japan.
authors.forename: Yukiko
authors.initials: Y
authors.lastname: Shinozaki
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Shigenobu
authors.initials: S
authors.lastname: Yoshida
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Motoo
authors.initials: M
authors.lastname: Koitabashi
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Yuka
authors.initials: Y
authors.lastname: Sameshima-Yamashita
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan.
authors.forename: Takeshi
authors.initials: T
authors.lastname: Fujii
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), Tsukuba Central 5-2, 1-1 Higashi, Tsukuba, Ibaraki 305-8565, Japan.
authors.forename: Tokuma
authors.initials: T
authors.lastname: Fukuoka
authors.affiliation: National Institute for Agro-environmental Sciences (NIAES), 3-1-3 Kannondai, Tsukuba, Ibaraki 305-8604, Japan. Electronic address: kitamoto@affrc.go.jp.
authors.forename: Hiroko Kuze
authors.initials: HK
authors.lastname: Kitamoto
mesh_terms: D063566:Biodegradable Plastics / Q000378:metabolism*; D019149:Bioreactors; D002265:Carboxylic Ester Hydrolases / Q000378:metabolism*; D004271:DNA, Fungal / Q000235:genetics; D005990:Glycerol / Q000378:metabolism; D016133:Polymerase Chain Reaction; D011108:Polymers / Q000378:metabolism; D014587:Ustilaginales / Q000201:enzymology*; D014994:Xylose / Q000378:metabolism*
chemical_list: D063566:Biodegradable Plastics; D004271:DNA, Fungal; D011108:Polymers; C574545:polybutylene succinate-co-adipate; D014994:Xylose; D002265:Carboxylic Ester Hydrolases; C019952:cutinase; D005990:Glycerol
keywords: Agricultural mulch film; Biodegradable plastics; Cutinase-like enzyme; Degradation; Jar-fermentor; Phyllosphere yeast; Pseudozyma antarctica; Xylose